How to fix the Oracle error PLS-00399: different types of columns in UNION, INTERSECT, or MINUS expression?

In this post, you’ll learn more about the Oracle ErrorPLS-00399: different types of columns in UNION, INTERSECT, or MINUS expression with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

PLS-00399: different types of columns in UNION, INTERSECT, or MINUS expression

Reason for the Error PLS-00399: different types of columns in UNION, INTERSECT, or MINUS expression

The select lists to the left and right of a UNION, INTERSECT, or MINUS expression select at least one column that is mismatched in datatype. For example, the following statement is faulty because the constant 3 has datatype NUMBER, whereas SYSDATE has datatype DATE: CURSOR my_cur IS SELECT 3 FROM emp INTERSECT SELECT SYSDATE FROM emp;

How to fix the Error PLS-00399: different types of columns in UNION, INTERSECT, or MINUS expression ?

You can fix this error in Oracle by following the below steps

Change the select lists so that they match in datatype. You might want to use datatype conversion functions in the select list of one or more queries.